Is choosing between Siemens and Omron solid-state relays really as simple as picking the more “famous” brand, or is there much more behind the decision than most engineers realize? When reliability, switching performance and long-term cost all hinge on this one component, can you afford to make a guess instead of an informed choice? If you’ve ever wondered which one truly fits your application—or whether either brand is objectively “better”—then the comparison below is exactly where you should start. Let’s dive deeper and uncover the real differences that actually matter.
Difference 1: Brand Positioning
Siemens: Siemens focuses on industrial-grade automation applications, emphasizing long-term reliability, integration with Siemens PLCs and drives, and strong global support—ideal for factories, heavy industry and power systems.
Omron: Omron specializes in control components and sensors, offering SSRs suitable for machine automation, packaging, semiconductor tools, and compact equipment requiring flexible configurations.
Difference 2: Product Lines and Model Coverage
Siemens: Provides industrial SSR modules for both AC and DC loads, optimized for cabinet or rail installation and high-power environments.
Omron: Offers a very wide range of SSRs—from PCB-level micro units to medium-power DIN-rail options—ideal for distributed control systems and machines with many channels.
Difference 3: Input Control Voltage
Siemens: Common industrial input ranges such as 3–32 VDC or 4–32 VDC, with strong electrical isolation and robust tolerance.
Omron: More flexible input ranges including 3–32 VDC and low-drive-current models compatible directly with microcontrollers or PLC outputs.
Difference 4: Output Types (AC and DC)
Siemens: Offers both AC and DC SSRs using SCRs, MOSFETs or IGBTs depending on model, with strong high-power AC switching capabilities.
Omron: Provides AC/DC SSR families as well, excelling in PCB-level DC MOSFET SSRs and medium-power AC modules.
Difference 5: Switching Mode (Zero-Cross vs. Random Turn-On)
Siemens: Supports both zero-cross and random-turn-on switching. Zero-cross reduces inrush and EMI; random-turn-on is suitable for phase control.
Omron: Also supplies clear zero-cross and random models with detailed application guidance for correct use.
Difference 6: On-State Voltage Drop and Leakage
Siemens: Designed for low voltage drop and stable leakage performance under high-power conditions; exact values depend on specific models.
Omron: Optimized voltage drop especially in MOSFET DC SSRs, providing detailed leakage and thermal curve data for engineering design.
Difference 7: Switching Speed
Siemens: Balances switching speed with surge resistance; some models support fast switching with well-defined delay specs.
Omron: Often offers quicker switching in compact SSRs, ideal for frequent switching and high-speed pulse control applications.
Difference 8: Mechanical Design and Mounting
Siemens: Rugged DIN-rail, panel-mounted, and modular cabinet designs suitable for large industrial systems.
Omron: Provides PCB-mount, panel-mount, and DIN-rail designs with additional accessories such as heatsinks and mounting adapters.
Difference 9: Thermal Management
Siemens: Offers detailed derating curves and heatsink recommendations for heavy-duty industrial cabinet use.
Omron: Supplies clear thermal guidance for compact installations, including PCB layout recommendations for heat dissipation.
Difference 10: Reliability and Lifetime
Siemens: Emphasizes long-term durability, offering MTBF and lifetime data for high-temperature and heavy-load conditions.
Omron: Also publishes reliability data, especially for machine automation and maintenance planning.
Difference 11: Pricing and Availability
Siemens: Generally higher in price due to industrial-grade positioning and global support services.
Omron: More cost-effective, especially for low/medium-power SSRs and multi-channel requirements.
How to Choose Between These Two Brands?
If you meet the following criteria, we recommend choosing Siemens:
If your system is a large industrial project requiring strict certifications, global after-sales support, or deep integration with Siemens automation, favor Siemens. For higher-power, long-term cabinet-level installations, Siemens is often more suitable. When selecting, match rated voltage/current, thermal requirements and environment, and follow Siemens datasheet derating curves and installation instructions.
If you meet the following conditions, it is recommended to choose Omron:
If your project involves machine building, many distributed control points, or emphasizes unit cost and flexible mounting (PCB or panel level), Omron is often more attractive. For fast switching, bulk purchasing or diverse packaging needs, prioritize Omron. During selection pay attention to trigger voltage/current, leakage, on-state voltage, mounting style and thermal conditions.
Conclusion
In summary, both Siemens and Omron solid-state relays have their advantages, and the choice depends on specific application requirements and budget. For those seeking a cost-effective and stable alternative, CDGKZ relay manufacturer is recommended. Their products are quite similar to the aforementioned brands in design and reliability, and with their rigorous manufacturing processes and excellent cost-performance ratio, they have become a reliable and wise choice for many engineers when selecting components.
